Opening means for sealed containers



July 28, 1954 H. N. BLAKESLEE 3,142,412

OPENING MEANS FOR SEALED CONTAINERS Filed Dec. 12, 1962 2 Sheets-Sheet 1 INVENTOR. fl/PEY ll/EZSflA/BZ/MESlff y 28, 1964 H. N. BLAKESL'EE 3,142,412

OPENING MEANS FOR SEALED CONTAINERS I Filed Dec. 12, 1962 I 2 Sheets- Sheet 2 2?? if id i/ fi INVENTOR.

IY/IPPY NEL 50/1/5l/ME'5LEE BY 5&4 119M Armin 5Y5 United States Patent 3 142 412 oPnNrNo MEANS non sEALEi) CONTAINERS Harry Nelson Blalreslee, Earrington, 111., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed Dec. 12, 1962, Ser. No. 244,076 10 Claims. (Cl. 220-54) The present invention relates to an easy to open container and more particularly to the construction of a tear strip end closure which is openable by hand.

A great deal of effort has been expended in recent years in the container industry in the development of easy open containers which do not require piercing or cutting tools to obtain access to the contents. This development has been motivated by a desire on the part of packers of such products as carbonated beverages, juices, vegetables, meat and other comestibles as well as many other products packed in vacuumized or pressurized containers for a container which, while possessing the necessary properties of hermeticity, strength and durability, provides the consumer with built-in means for opening the container and removing its contents with the greatest possible ease. Several constructions have evolved which, in general, feature a metal end closure of a soft material such as aluminum or aluminum alloy and which is appropriately scored or otherwise weakened to provide a detachable portion.

In view of the requirement that the entire container, including the end closure, be sufiiciently strong to withstand static forces encountered in processing the product as well as normal handling and shipping of the container, it will be recognized that there is inherent incompatibility between the requirement of container strength and the desire for an end closure that is easily opened. That is, if the metal closure is deeply scored to provide greater ease of detachment, the strength of the container is proportionately impaired. Conversely, only lightly scoring of weakening the closure so as not to excessively impair its strength characteristics means that the consumer must tear through a greater thickness of metal to open the container.

It is therefore an object of the present invention to provide a high strength container end closure which is openable by hand.

Another object of this invention is to provide a container with an end closure having a detachable tear strip, which closure is of high strength construction and yet is easily opened to provide access to the contents of the container without the need of an opening tool.

Yet another object of this invention is to provide an easy to open end closure which is easily and inexpensively manufactured at high rates of production.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

With the foregoing objects in view, the invention provides an end closure comprising a sealing ring having a rim portion adapted to be seamed to a container body and a transversal portion projecting a predetermined'distance inwardly of the rim portion, an integral tear strip in the innermost marginal edge of this transversal portion defined by a line of weakness extending therearound, and a panel detachably sealed to the ring in underlying engagement with the tear strip inwardly of the line of weakness defining the tear strip.

Referring to the drawings:

FIG. 1 is a perspective view of a container constructed in accordance with the present invention.

FIG. 2 is a top end view of the container of FIG. 1.

3,142,412 Patented July 28, 1964 FIG. 3 is an enlarged, fragmentary sectional view taken substantially along lines 33 of FIG. 1.

FIG. 4 is a perspective view illustrating the container of FIG. 1 with the end closure in detached relation.

FIG. 5 is an enlarged, fragmentary sectional view of a modified embodiment of the present invention.

FIG. 6 is an enlarged, fragmentary sectional view of still another embodiment of the invention.

As a preferred or exemplary embodiment of the instant invention, FIG. 1 shows a container comprising a tubular body generally designated 10 and a top end closure generally designated 11 secured to the body 10 by means of an interlocking end seam 12. Body 10 may be of any conventional construction and is here shown in a cylindrical configuration with a side seam 13 extending from end to end which is typical of the well known metal can construction. Obviously, body 10 may be made by other means such as impact extrusion or of materials other than metal, examples being plastic, fibre, and various fibre laminations either spirally or convolutely wound into tubular configuration.

Top end closure 11 itself comprises two main components, the first of which is an annular ring or band generally designated 14 and the other being a central discshaped panel 15 sealed to the underneath surface of ring 14. By the word annular as used herein is meant any continuous configuration coinciding with the geometry of tubular body 10, whether circular, oval, square or obrotund in transverse cross-section. Ring 14 comprises a peripheral rim portion 14a which is adapted to be double seamed to body 10 as at 12 and a transversal portion 14b which projects a predetermined distance inwardly from rim portion 14a to overlie the peripheral margin of panel 15. Preferably, the peripheral edge of panel 15 is hemmed or curled upwardly and inwardly as at 15a to protect its cut edge from exposure to the contents of the container.

In the embodiment illustrated in FIG. 3, a thin, annular band 16 of adhesive is applied between the surfaces of the marginal edge of panel 15 and transversal portion 14b of ring 14 to secure the two components together in sealed engagement. This adhesive may be any suitable type capable of effecting a fluid-tight seal between the cooperating surfaces of ring 14 and panel 15, but, preferably is of low peel strength to permit easy disengagement of these members when the container is to be opened. Examples of such an adhesive are heat scalable polyesters, acrylic acid-polyethylene copolymers, and resin-rubber compounds.

A single line of weakness 17, preferably formed by scoring the metal, extends circumferentially about ring 14 intermediate portions 14a and 1412. This score line 17 provides an integral tear strip 18 in the innermost margin of transversal portion 14b of the ring. Portion 14b and panel 15 are appropriately dimensioned so that the tear strip 18 overlies the marginal edge of panel 15 about its entire periphery so that the panel is secured by adhesive 16 to the underneath surface of the tearing strip inwardly of score line 17. Preferably, the score line is formed in ring 14 as close as possible to the juncture of portions 14a and 1411 so that the potentially dangerous raw edge remaining after tear strip 18 is detached does not extend too far inwardly from rim portion 14a.

As shown in FIG. 2, ring 14 is also provided with a pull tab 19 integral with one end of tear strip 18, this tab projecting inwardly over panel 15 and providing finger-grip means for detaching the tear strip from the container. Preferably, the circumferentially opposite end of the tearing strip 18 is provided with another but smaller inwardly projecting tab 20 which is spot welded or otherwise permanently secured to disc 15 as at 21. Permanently secured tab 20 lies adjacent to and is set off from \& pull tab 19 by a score line 17a which extends outwardly from a juncture point 22 where the edges of the two tabs meet and merges with continuous, circumferential score line 17.

In this form of construction, closure 11 may be removed easily and quickly in the manner illustrated in FIG. 4 by grasping pull tab 19 and pulling it first upwardly and outwardly to tear through score line 17a and then circumferentially about the container along score line 17 By this movement, the tear strip 18 is peeled away from its securement with panel 15 except at 21 and simultaneously is detached from the container. Spot weld 21 retains panel 15 to the terminal end of the tear strip 18 so that the two may be lifted out of the open end of the container together, thereby providing access to a product P contained therein.

It will be appreciated that a principal advantage of the tear strip closure construction just descrbed is in the fact that a single score line 17 provides a circumferentially detachable tear strip. This means that the consumer, to open the container, is required to tear through only that portion of metal lying directly beneath the score line 17. This is an improvement over prior art constructions where opening is accomplished either by detaching a tear strip defined by two parallel score lines or removing a portion of an end panel by tearing along a single continuous line of weakness in opposite directions from a common point of origin, in either case requiring the consumer to tear the metal at two points simultaneously. In effect then, the present invention provides a construction wherein the score line defining the detachable tear strip need not be cut as deeply into the metal to ensure easy manual removal since the consumer ha proportionately less metal to rip through at any one instant during the opening motion. Accordingly, the shallower score line 17 provides for a stronger, rupture-proof end closure but with improved ease of opening.

Preferably, annular ring 14 in which score 17 is formed to provide the tear strip 18 is a soft metal, such as aluminum or an aluminum alloy, but it will be understood that other metals, such as steel, as well as non metals, such as high strength plastics and fibres, may be used. Although not as high in shear strength as the tin plate or black plate ordinarily used for container construction, a closure of aluminum or its alloy will withstand the forces to which the container is normally subjected since the use of a single score line does not require as deep a cut to enable easy detachment by hand. On the other hand, panel 15 may be steel, iron plate, or other high strength material and of sufiicient thickness to withstand any internal and/ or external forces tending to buckle the closure.

FIGS. and 6 illustrate alternate embodiments of the present invention having the addition of a reclosure feature. In the embodiment illustrated in FIG. 5, end closure generally designated 31 comprises annular ring 34 having a rim portion 34a and a transversal portion 34b identical in all respects to that of the FIG. 3 embodiment hereinabove described. A reclosure panel 35 having a central, upstanding knob 40 or similar means for gripping is secured to the underneath surface of a circumferential tear strip 38 set off by a score line 37 formed near the juncture of rim portion 34a and transversal portion 34b. Rim portion 34a is double seamed at 32 to a container body generally designated 30 in the same manner as in the preferred embodiment. However, the body 30 is provided with an inwardly projecting collapsed bead 39 immediately below end seam 32, which beads underlies and forms a supporting ledge for the marginal edge of end panel 35. Collapsed bead 39 is positioned below transversal portion 34b a predetermined distance sufficient to support end panel 35 in tight engagement with the underneath side of tear strip 38. A thin, annular band 36 of sealing material, such as plastisol or other type of gasketing compound, is disposed between the coacting surfaces of tear strip 38 and panel to provide the hermetic seal. Preferably, gasket 36 is bonded to the underneath surface of transversal portion 34b and extends outwardly far enough to underlie score line 37. When tear strip 38 is detached, material 36 adheres to the strip and helps to shield the tear edge to protect the user against injury. If the product is vacuum packed, removal of sealing band 36 with detachment of the tear strip breaks the vacuum and enables easy removal of closure panel 35.

Upon detachment of tear strip 38, which is provided with a finger-grip pull tab (not shown) as in the previous embodiment, closure panel 35 may be lifted out of the end of the container by means of knob to provide access to its contents and thereafter replaced onto the container as a reclosure. Since this construction is intended to function as a reclosure, the terminal end of tear strip 38 is not spot welded to panel 35 as in the previous embodiment.

In the FIG. 6 embodiment, a closure generally designated 51 is double seamed as at 52 to a body in the same manner as hereinbefore described, but the annular closure ring 54 is constructed to provide the supporting ledge for panel 55. In this case, the transversal portion 54b inwardly of peripheral end portion 54a is triple-folded as shown to provide a double-fold or ledge 59 below the panel 55 and a single fold above the panel. A circumferential score 57 formed in transversal portion 54b between the single-fold and double-fold sections provides an integral tear strip 58 overlying the marginal edge of panel 55. The panel is provided with an upstanding annular wall 55a inwardly of its peripheral edge, which wall frictionally engages with the inner edge of ledge 59 to provide an air-tight reclosure seal. An annular gasket 56 is disposed between the coacting surfaces of panel 55 and tear strip 58 to provide the necessary hermeticity. Instead of the central knob 40 of the preceding embodiment, closure panel 55 may be provided with a plastic knob 60 secured centrally of the panel by a suitable adhesive 61 to provide means for lifting the panel 55 from the container after detachment of tear strip 58 and for replacing the panel onto the container as a reclosure.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction, and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. A can cover comprising a sealing ring having a peripheral rim portion adapted for securement to a can body and a transversal portion inwardly of said rim portion, said ring having a line of weakness intermediate said portions defining an integral tear strip in said transversal portion, and a panel underlying and detachably secured to said tear strip inwardly of said line of weakness.

2. The cover of claim 1 wherein said ring is aluminum alloy.

3. The cover of claim 1 and including a sealing material securing said panel to said tear strip.

4. The cover of claim 1 wherein a terminal end of said tear strip is permanently attached to said panel.

5. A can cover comprising an annular ring having a peripheral rim portion adapted for securement to a can body and a transversal portion inwardly of said rim portion, a panel detachably secured to said transversal portion, and an integral tear strip extending about the innermost margin of said transversal portion and overlying the marginal edge of said panel, said tear strip being defined by a line of weakness extending about said ring intermediate said portions and having a pull tab integral therewith.

6. A container having an easy-open end closure, cofnprising a tubular body, an annular ring secured to one end of said body in an end seam, said ring having a transversal portion projecting inwardly of and extending about the wall of said body, and a separate panel extending across said end in underlying securement with said transversal portion, said ring having a line of weakness in said transversal portion defining an integral tear strip overlying the marginal edge of said panel.

7. The container of claim 6 and including a sealing material securing said panel to the underneath surface of said tear strip.

8. The container of claim 6 wherein said body includes an indentation below said seam supporting said panel in underlying securement with said transversal portion.

9. The container of claim 6 wherein said transversal portion comprises a first fold projecting inwardly in underlying engagement with said panel and a second fold overlying the edge of said panel, said tear strip being in said second fold.

10. A container having an easy open end with reclosure capability, comprising a tubular body, a ring secured to one end of said body in an interfolded seam, an indentation projecting inwardly of said seam, a closure panel supported on said indentation, said ring having a transversal portion with a weakened, detachable tear strip overlying the peripheral margin of said panel, and a gasket material interposed between said tear strip and said peripheral margin of said panel to seal said container.

References Cited in the file of this patent UNITED STATES PATENTS 2,149,308 Peckham Mar. 7, 1939 2,673,806 Colman Mar. 30, 1954 

1. A CAN COVER COMPRISING A SEALING RING HAVING A PERIPHERAL RIM PORTION ADAPTED FOR SECUREMENT TO A CAN BODY AND A TRANSVERSAL PORTION INWARDLY OF SAID RIM PORTION, SAID RING HAVING A LINE OF WEAKNESS INTERMEDIATE SAID PORTIONS DEFINING AN INTEGRAL TEAR STRIP IN SAID TRANSVERSAL PORTION, AND A PANEL UNDERLYING AND DETACHABLY 